I have read many places that 2005 E's will play mp3 on cd. I have done the 3-5-7 menu trick and set the keyboard to w211ece. I place my cdr with mp3's in the cd slot and all I get is "cd error" or "not audio cd".

There is nothing your doing wrong it will play no matter what. Mines play mp3 all you have to do is make sure all the files you are burning from your computer to the cd are in mp3 format. other than that you should have no problems. make sure they are not in wma files cuz the cd player will not read it. and the kool thing about it is that u can catagorize your files in different folders before you burn it so when you play it in your car you can select from different folders. the best type of cd to use is the black ones. the ones wiht the black face they seem to read a little more better. cuz the regular cd will sometimes skip. enjoy your car and the mp3 player in it.....[:D]